[PATCH v11 2/3] phy: qcom-snps: Add support for overriding phy tuning parameters

[Krishna Kurapati <quic_kriskura@quicinc.com>]

Add support for overriding electrical signal tuning parameters for
SNPS HS Phy.

Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Reviewed-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
---
 drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c | 262 +++++++++++++++++++++++++-
 1 file changed, 260 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
index 5d20378..24264ad 100644
--- a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
+++ b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
@@ -52,6 +52,12 @@
 #define USB2_SUSPEND_N				BIT(2)
 #define USB2_SUSPEND_N_SEL			BIT(3)
 
+#define USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X0		(0x6c)
+#define USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X1		(0x70)
+#define USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X2		(0x74)
+#define USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X3		(0x78)
+#define PARAM_OVRD_MASK				0xFF
+
 #define USB2_PHY_USB_PHY_CFG0			(0x94)
 #define UTMI_PHY_DATAPATH_CTRL_OVERRIDE_EN	BIT(0)
 #define UTMI_PHY_CMN_CTRL_OVERRIDE_EN		BIT(1)
@@ -60,12 +66,69 @@
 #define REFCLK_SEL_MASK				GENMASK(1, 0)
 #define REFCLK_SEL_DEFAULT			(0x2 << 0)
 
+#define HS_DISCONNECT_MASK			GENMASK(2, 0)
+#define SQUELCH_DETECTOR_MASK			GENMASK(7, 5)
+
+#define HS_AMPLITUDE_MASK			GENMASK(3, 0)
+#define PREEMPHASIS_DURATION_MASK		BIT(5)
+#define PREEMPHASIS_AMPLITUDE_MASK		GENMASK(7, 6)
+
+#define HS_RISE_FALL_MASK			GENMASK(1, 0)
+#define HS_CROSSOVER_VOLTAGE_MASK		GENMASK(3, 2)
+#define HS_OUTPUT_IMPEDANCE_MASK		GENMASK(5, 4)
+
+#define LS_FS_OUTPUT_IMPEDANCE_MASK		GENMASK(3, 0)
+
 static const char * const qcom_snps_hsphy_vreg_names[] = {
 	"vdda-pll", "vdda33", "vdda18",
 };
 
 #define SNPS_HS_NUM_VREGS		ARRAY_SIZE(qcom_snps_hsphy_vreg_names)
 
+struct override_param {
+	s32	value;
+	u8	reg;
+};
+
+#define OVERRIDE_PARAM(bps, val) {	\
+	.value = bps,			\
+	.reg = val,			\
+}
+
+struct override_param_map {
+	const struct override_param *param_table;
+	u8 table_size;
+	u8 reg_offset;
+	u8 param_mask;
+};
+
+#define OVERRIDE_PARAM_MAP(table, num_elements, offset, mask)		\
+{									\
+	.param_table = table,						\
+	.table_size = num_elements,					\
+	.reg_offset = offset,						\
+	.param_mask = mask,						\
+}
+
+struct phy_override_seq {
+	bool	need_update;
+	u8	offset;
+	u8	value;
+	u8	mask;
+};
+
+static const char * const phy_seq_props[] = {
+	"qcom,hs-disconnect-bp",
+	"qcom,squelch-detector-bp",
+	"qcom,hs-amplitude-bp",
+	"qcom,pre-emphasis-duration-bp",
+	"qcom,pre-emphasis-amplitude-bp",
+	"qcom,hs-rise-fall-time-bp",
+	"qcom,hs-crossover-voltage-microvolt",
+	"qcom,hs-output-impedance-micro-ohms",
+	"qcom,ls-fs-output-impedance-bp",
+};
+
 /**
  * struct qcom_snps_hsphy - snps hs phy attributes
  *
@@ -91,6 +154,7 @@ struct qcom_snps_hsphy {
 
 	bool phy_initialized;
 	enum phy_mode mode;
+	struct phy_override_seq update_seq_cfg[ARRAY_SIZE(phy_seq_props)];
 };
 
 static inline void qcom_snps_hsphy_write_mask(void __iomem *base, u32 offset,
@@ -173,10 +237,147 @@ static int qcom_snps_hsphy_set_mode(struct phy *phy, enum phy_mode mode,
 	return 0;
 }
 
+static const struct override_param hs_disconnect_sc7280[] = {
+	OVERRIDE_PARAM(-272, 0),
+	OVERRIDE_PARAM(0, 1),
+	OVERRIDE_PARAM(317, 2),
+	OVERRIDE_PARAM(630, 3),
+	OVERRIDE_PARAM(973, 4),
+	OVERRIDE_PARAM(1332, 5),
+	OVERRIDE_PARAM(1743, 6),
+	OVERRIDE_PARAM(2156, 7),
+};
+
+static const struct override_param squelch_det_threshold_sc7280[] = {
+	OVERRIDE_PARAM(-2090, 7),
+	OVERRIDE_PARAM(-1560, 6),
+	OVERRIDE_PARAM(-1030, 5),
+	OVERRIDE_PARAM(-530, 4),
+	OVERRIDE_PARAM(0, 3),
+	OVERRIDE_PARAM(530, 2),
+	OVERRIDE_PARAM(1060, 1),
+	OVERRIDE_PARAM(1590, 0),
+};
+
+static const struct override_param hs_amplitude_sc7280[] = {
+	OVERRIDE_PARAM(-660, 0),
+	OVERRIDE_PARAM(-440, 1),
+	OVERRIDE_PARAM(-220, 2),
+	OVERRIDE_PARAM(0, 3),
+	OVERRIDE_PARAM(230, 4),
+	OVERRIDE_PARAM(440, 5),
+	OVERRIDE_PARAM(650, 6),
+	OVERRIDE_PARAM(890, 7),
+	OVERRIDE_PARAM(1110, 8),
+	OVERRIDE_PARAM(1330, 9),
+	OVERRIDE_PARAM(1560, 10),
+	OVERRIDE_PARAM(1780, 11),
+	OVERRIDE_PARAM(2000, 12),
+	OVERRIDE_PARAM(2220, 13),
+	OVERRIDE_PARAM(2430, 14),
+	OVERRIDE_PARAM(2670, 15),
+};
+
+static const struct override_param preemphasis_duration_sc7280[] = {
+	OVERRIDE_PARAM(10000, 1),
+	OVERRIDE_PARAM(20000, 0),
+};
+
+static const struct override_param preemphasis_amplitude_sc7280[] = {
+	OVERRIDE_PARAM(10000, 1),
+	OVERRIDE_PARAM(20000, 2),
+	OVERRIDE_PARAM(30000, 3),
+	OVERRIDE_PARAM(40000, 0),
+};
+
+static const struct override_param hs_rise_fall_time_sc7280[] = {
+	OVERRIDE_PARAM(-4100, 3),
+	OVERRIDE_PARAM(0, 2),
+	OVERRIDE_PARAM(2810, 1),
+	OVERRIDE_PARAM(5430, 0),
+};
+
+static const struct override_param hs_crossover_voltage_sc7280[] = {
+	OVERRIDE_PARAM(-31000, 1),
+	OVERRIDE_PARAM(0, 3),
+	OVERRIDE_PARAM(28000, 2),
+};
+
+static const struct override_param hs_output_impedance_sc7280[] = {
+	OVERRIDE_PARAM(-2300000, 3),
+	OVERRIDE_PARAM(0, 2),
+	OVERRIDE_PARAM(2600000, 1),
+	OVERRIDE_PARAM(6100000, 0),
+};
+
+static const struct override_param ls_fs_output_impedance_sc7280[] = {
+	OVERRIDE_PARAM(-1053, 15),
+	OVERRIDE_PARAM(-557, 7),
+	OVERRIDE_PARAM(0, 3),
+	OVERRIDE_PARAM(612, 1),
+	OVERRIDE_PARAM(1310, 0),
+};
+
+static const struct override_param_map sc7280[] = {
+	OVERRIDE_PARAM_MAP(
+			hs_disconnect_sc7280,
+			ARRAY_SIZE(hs_disconnect_sc7280),
+			USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X0,
+			HS_DISCONNECT_MASK),
+
+	OVERRIDE_PARAM_MAP(
+			squelch_det_threshold_sc7280,
+			ARRAY_SIZE(squelch_det_threshold_sc7280),
+			USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X0,
+			SQUELCH_DETECTOR_MASK),
+
+	OVERRIDE_PARAM_MAP(
+			hs_amplitude_sc7280,
+			ARRAY_SIZE(hs_amplitude_sc7280),
+			USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X1,
+			HS_AMPLITUDE_MASK),
+
+	OVERRIDE_PARAM_MAP(
+			preemphasis_duration_sc7280,
+			ARRAY_SIZE(preemphasis_duration_sc7280),
+			USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X1,
+			PREEMPHASIS_DURATION_MASK),
+
+	OVERRIDE_PARAM_MAP(
+			preemphasis_amplitude_sc7280,
+			ARRAY_SIZE(preemphasis_amplitude_sc7280),
+			USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X1,
+			PREEMPHASIS_AMPLITUDE_MASK),
+
+	OVERRIDE_PARAM_MAP(
+			hs_rise_fall_time_sc7280,
+			ARRAY_SIZE(hs_rise_fall_time_sc7280),
+			USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X2,
+			HS_RISE_FALL_MASK),
+
+	OVERRIDE_PARAM_MAP(
+			hs_crossover_voltage_sc7280,
+			ARRAY_SIZE(hs_crossover_voltage_sc7280),
+			USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X2,
+			HS_CROSSOVER_VOLTAGE_MASK),
+
+	OVERRIDE_PARAM_MAP(
+			hs_output_impedance_sc7280,
+			ARRAY_SIZE(hs_output_impedance_sc7280),
+			USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X2,
+			HS_OUTPUT_IMPEDANCE_MASK),
+
+	OVERRIDE_PARAM_MAP(
+			ls_fs_output_impedance_sc7280,
+			ARRAY_SIZE(ls_fs_output_impedance_sc7280),
+			USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X3,
+			LS_FS_OUTPUT_IMPEDANCE_MASK),
+};
+
 static int qcom_snps_hsphy_init(struct phy *phy)
 {
 	struct qcom_snps_hsphy *hsphy = phy_get_drvdata(phy);
-	int ret;
+	int ret, i;
 
 	dev_vdbg(&phy->dev, "%s(): Initializing SNPS HS phy\n", __func__);
 
@@ -223,6 +424,14 @@ static int qcom_snps_hsphy_init(struct phy *phy)
 	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_HS_PHY_CTRL1,
 					VBUSVLDEXT0, VBUSVLDEXT0);
 
+	for (i = 0; i < ARRAY_SIZE(hsphy->update_seq_cfg); i++) {
+		if (hsphy->update_seq_cfg[i].need_update)
+			qcom_snps_hsphy_write_mask(hsphy->base,
+					hsphy->update_seq_cfg[i].offset,
+					hsphy->update_seq_cfg[i].mask,
+					hsphy->update_seq_cfg[i].value);
+	}
+
 	qcom_snps_hsphy_write_mask(hsphy->base,
 					USB2_PHY_USB_PHY_HS_PHY_CTRL_COMMON2,
 					VREGBYPASS, VREGBYPASS);
@@ -280,7 +489,10 @@ static const struct phy_ops qcom_snps_hsphy_gen_ops = {
 static const struct of_device_id qcom_snps_hsphy_of_match_table[] = {
 	{ .compatible	= "qcom,sm8150-usb-hs-phy", },
 	{ .compatible	= "qcom,usb-snps-hs-5nm-phy", },
-	{ .compatible	= "qcom,usb-snps-hs-7nm-phy", },
+	{
+		.compatible	= "qcom,usb-snps-hs-7nm-phy",
+		.data		= &sc7280,
+	},
 	{ .compatible	= "qcom,usb-snps-femto-v2-phy",	},
 	{ }
 };
@@ -291,6 +503,51 @@ static const struct dev_pm_ops qcom_snps_hsphy_pm_ops = {
 			   qcom_snps_hsphy_runtime_resume, NULL)
 };
 
+static void qcom_snps_hsphy_override_param_update_val(
+			const struct override_param_map map,
+			s32 dt_val, struct phy_override_seq *seq_entry)
+{
+	int i;
+
+	/*
+	 * Param table for each param is in increasing order
+	 * of dt values. We need to iterate over the list to
+	 * select the entry that has equal or the next highest value.
+	 */
+	for (i = 0; i < map.table_size - 1; i++) {
+		if (map.param_table[i].value == dt_val)
+			break;
+	}
+
+	seq_entry->need_update = true;
+	seq_entry->offset = map.reg_offset;
+	seq_entry->mask = map.param_mask;
+	seq_entry->value =  map.param_table[i].reg << __ffs(map.param_mask);
+}
+
+static void qcom_snps_hsphy_read_override_param_seq(struct device *dev)
+{
+	struct device_node *node = dev->of_node;
+	s32 val;
+	int ret, i;
+	struct qcom_snps_hsphy *hsphy;
+	const struct override_param_map *cfg = of_device_get_match_data(dev);
+
+	hsphy = dev_get_drvdata(dev);
+
+	for (i = 0; i < ARRAY_SIZE(phy_seq_props); i++) {
+		ret = of_property_read_s32(node, phy_seq_props[i], &val);
+		if (ret)
+			continue;
+
+		qcom_snps_hsphy_override_param_update_val(cfg[i], val,
+					&hsphy->update_seq_cfg[i]);
+		dev_dbg(&hsphy->phy->dev, "Read param: %s dt_val: %d reg_val: 0x%x\n",
+			phy_seq_props[i], val, hsphy->update_seq_cfg[i].value);
+
+	}
+}
+
 static int qcom_snps_hsphy_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -352,6 +609,7 @@ static int qcom_snps_hsphy_probe(struct platform_device *pdev)
 
 	dev_set_drvdata(dev, hsphy);
 	phy_set_drvdata(generic_phy, hsphy);
+	qcom_snps_hsphy_read_override_param_seq(dev);
 
 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 	if (!IS_ERR(phy_provider))
-- 
2.7.4